After converting the aptosid-squeeze setup to nfs4 it all seemed to work until I noticed that idmapping was broken and all files on the nfs drives belonged to nouser:nogroup (which had interesting effects on the backup that is made via nfs on that system...).

I reverted the system to nfs-common 1.2.2 from the testing repo and put nfs-common on "hold", that worked.

As info regarding the hanging boot when starting statd: This just happens about every second boot. After a reset the kernel may boot again, so that you do not need any special tricks to get into the system for installing rpcbind.